Static Type System

Notes for the design of a static type system

The static type system provides compile time constraints in the forms of sets of static values.

Set types (static types) are provided as a set of static values between ||.

|"red","green",1:20|

In the above example the value being constrained can be either "red", "green" or in the range 1:20.

Any value can be supplied in the constraint as long as it is a static value.

Type intersection

|"red","green"| b;
|"red","green",1:20| a  = b; //correct b is a subset of a
|"red"| a  = b; //error b is not a subset of a
|1:20| a = 4; // correct 4 is a subset of 1:20
|1:10,15:20| a = 12; // error 12 is not a subset of |1:10,15:20| 
|"red","green",1:10| c;
|"red","green",1:20| a= c; //correct c is a subset of a